PPI-BoreAid is an online tool developed for
and released by the Plastics Pipe Institute (PPI). These tools
are developed to assist industry professionals in the evaluation
of PE pipe for installation using a horizontal directional drill
(HDD) by completing Handbook of PE Pipe, 2nd Edition Chapter 12
design calculations. PE pipe operation and installation
calculations (deflection, unconstrained collapse, compressive
wall stress, pull back force, and maximum tensile stress) are
performed using a user defined bore path and soil strata.
PPI-BoreAid employs the calculation methodology and framework
developed in BOREAID™ - a comprehensive HDD design tool.
BOREAID™ is capable of performing a full HDD design and
deformation analysis using 3D surface topography, complex site
stratigraphy, with full control over pipe and soil properties.
It also contains as-built plots, the ability to export
drill rod-by-rod plans, AutoCad import and export compatibility,
a drill fluid estimator, a limiting bore pressure estimator, a
project cost estimator and an equipment selector. For more
information on BoreAid, visit www.boreaid.com.
Input
Calculated Values
WARNING
The length traversed at depth is less than zero. This is not a valid bore geometry. To create a valid bore, either decrease the depth of cover or increase the pipe entry/exit angles.
The results table will not be updated until this problem is fixed.
The earth pressure coefficient used in the calculations is based upon Stein’s theory.
The safe pull stress is calculated based upon minimum tensile stress requirements for PE 2406 (PE234373), PE3608 (PE345464), and PE4710 (PE445574) as outlined in ASTM D3350 - 10a Standard Specification for Polyethylene Plastics Pipe and Fittings Materials.
The operational critical collapse calculation displays the result for a water filled pipe (i.e., pressure pipe) and empty pipe (i.e., conduit, gravity-sewer).
Operational compressive wall stress and buoyant deflection during installation are not shown.
¾ of the maximum calculated tensile stress is used in the installation critical collapse calculation since the maximum depth is typically not encountered past three-quarters of the bore distance.
Entry and exit elevations are assumed equal and additional loads due to variation in topography are not considered (topography is flat).
The silo width is assumed equal to the bore diameter for calculation of the arching factor during determination of the earth pressure.
The 1-hr installation critical collapse pressure includes the drag pressure but the 10-hr calculation does not.
The installation critical collapse calculations assume a pipe ovality of 3%. The operational critical collapse calculations use the larger of 3% and the earth pressure deflection.
For bores in lithified rock, the earth pressure and deflection are not calculated but an ovality deflection of 3% is assumed for collapse calculations. The long term safety factor against collapse is calculated using a slurry unit weight of 93.57 pcf.
These are preliminary calculations only. Qualified professionals should be contracted to consider all aspects of the design for horizontal directional drilling.
NOTE: For design information contained in Chapter 12 of the Handbook of PE Pipe, Second Edition published by the Plastic Pipe Institute (PPI) click on the hyperlinked labels.
